Japanese Patent Application Publication No. 2012-163099 describes a fuel pump that supplies fuel to a vehicle engine. The fuel pump includes an impeller having a plurality of blades arranged along a circumferential direction. Blade grooves are provided between respective pairs of adjacent blades. The plurality of blades and the plurality of blade grooves are arranged on both surfaces of the impeller. Each of the plurality of blade grooves arranged on one of the surfaces of the impeller communicates with a corresponding one of the plurality of blade grooves arranged on the other surface of the impeller.